1. Field of the Invention
The present invention relates to a disc clamping apparatus for a disc player, and more particularly to a disc clamping apparatus of a compact disc player used in a vehicle.
2. Description of the Prior Art
In general, an optical disc player records and reproduces information on and from an optical disc using an optical pick-up which is installed under an optical disc. In the optical disc player, the optical disc is positioned on a turntable which is rotated by a spindle motor and is clamped by a clamping apparatus so as to be stably rotated even when external impacts are exerted thereto.
Recently, such an optical disc player has been used in a vehicle as well as for domestic use. In a vehicular optical disc player, while a vehicle to which the optical disc player is mounted is travelling on a road, vibrational forces can be exerted to the disc player, so a clamping apparatus is needed to stably clamp the optical disc.
FIGS. 1 and 2 show a conventional disc player 200 for a vehicle. FIG. 1 is a plan view of disc player 200, and FIG. 2 is a side sectional view of disc player 200 shown in FIG. 1.
As shown in FIGS. 1 and 2, the conventional vehicular disc player 200 includes a base 210. A disc insertion hole 212 through which a disc (not shown) is inserted and ejected is provided on one side of base 210. To the upper surface of the base is fixedly attached a first cover plate 220 which covers about half the upper surface of base 210 on the front side of base 210 which is adjacent to the disc insertion hole 212. A second cover plate 230 is hinged to the upper surface of base 210 on the rear side of base 210.
The second cover plate 230 is downwardly urged by a spring provided on the rear side of base 210.
A hinge shaft 234 is provided to the rear of a first side of second cover plate 230, and second cover plate 230 is hinged to base 210 by hinge shaft 234. A guide shaft 232 is provided to the front of a second side of a second cover plate 230, which is opposite to the first side thereof. Guide shaft 232 is supported on a movable plate 240 provided on one side of base 210. Movable plate 240 is moved by a separate gear mechanism (not shown) to the front or rear side of base 210. Guide shaft 232 is selectively supported on upper or lower portion 242 or 244 of movable plate 240 when movable plate 240 is moved, and the front portion of second plate 230 is thus upwardly or downwardly movable.
A clamp suspension 250 is integrally formed in a front end portion of second cover plate 230. Clamp suspension 250 is protruded by a distance from the front end portion of second cover plate 230 toward the center of base 210. A slot 254 for attaching a clamp 300 to clamp suspension 250 is formed in clamp suspension 250, and a serpentine portion 252 which extends along the center of slot 254 in a longitudinal direction of slot 254 is integrally provided in clamp suspension 250 above slot 254. The free end of serpentine portion 252 makes contact with clamp 300 so that clamp 300 stably clamps the disc.
As particularly shown in FIG. 2, clamp 300 includes an annular plate 260 which makes contact with the upper surface of the disc, a neck portion 262 which is provided on annular plate 260 and press-fitted into slot 254 of clamp suspension 250, and a support portion 264 which is provided on neck portion 262 and positioned on the upper surface of clamp suspension 250, and a boss 266 which is protruded at the center portion of the upper surface of support portion 264 so as to make contact with the free end of serpentine portion 252.
At the central portion of the lower surface of base 210 is provided a spindle motor 270 for rotating turntable 280.
Hereinafter, the operation of the conventional vehicular disc player 200 will be explained.
Firstly, when disc player 200 is not in operation, that is, the disc hs been ejected from disc player 200, guide shaft 232 is supported on upper end portion 242 of movable plate 240, and the front portion of second cover plate 230, as shown in FIG. 2, remains upwardly moved.
In this state, when the disc is inserted into disc insertion hole 212, the disc is guided into the interior of disc player 200 and positioned on turntable 280 by a disc loading mechanism (not shown) such as a gear mechanism or the like. Then, movable plate 240 is moved to the front of base 210 by a separate gear mechanism. As movable plate 240 is moved to the front of base 210, guide shaft 232 supported on upper end portion 242 of movable plate 240 is supported on lower end portion 244 of movable plate 240, and the front portion of second cover plate 230 is moved downward.
As a result, annular plate 260 of clamp 300 makes contact with the upper surface of the disc positioned on turntable 280, and a bending portion 252 which is integrally formed in clamp suspension 250 by a spring installed on the front side of base 210 downwardly urges boss 266 provided on the upper surface of clamp 300 to stably clamp the upper surface of the disc.
However, in the conventional vehicular disc player 200, when disc player 200 is not in operation, clamp 300 collides with the lower surface of first cover plate 220 during the running of the vehicle, causing rattle noise.
In addition, a hook portion having elasticity should be formed on neck portion 262 of clamp 300 in order to assemble clamp 300 in slot 254 of clamp suspension 250, so the manufacturing process of clamp 300 is complicated.
Moreover, when disc player 200 is not in operation, the clamp 300 remains upwardly tilted toward disc insertion hole 210, so the disc makes contact with clamp 300 during insertion of the disc, and as a result, the disc cannot be positioned on turntable 280.